Researchers from the University of California, Berkley managed to successfully extract clean, drinkable water at very low humidity and at a low cost using their newly built next-generation water harvester.
Omar Yaghi, the James and Neeltje Tretter chair in chemistry at UC Berkeley and inventor of the technology said: “There is nothing like this.
“It operates at ambient temperature with ambient sunlight, and with no additional energy input you can collect water in the desert.
“This laboratory-to-desert journey allowed us to really turn water harvesting from an interesting phenomenon into a science.”
In October 2017, scientists created a prototype water harvester, which they propped into the backyard of a tract home as the device sucked water out of the air using just sunlight as energy.
Their initial discovery led them to create an even larger water extractor machine, brining them closer to their goal of providing life-long clean and drinkable water to people living in water-scarce areas.
Mr Yaghi, a faculty scientist at Lawrence Berkeley National Laboratory, and his team are set to report the results of the water-collecting harvester’s first field test in the June 8 edition of the scientific journal, Science Advances.
The trial was conducted in Scottsdale, where the relative humidity drops as low as 8 percent a day.
Despite low humidity levels, the harvester demonstrated its ability to extract water from even the most scarce places, after scientists added more of the machine’s water absorber – a highly porous material comprising of a metal-organic framework, or MOF.
Researchers estimate that the harvester’s current MOF (MOF-801), made out of the expensive metal zirconium, will be able to extract about 200 millilitres of water per kilogram of MOF.
Mr Yaghi also created a new MOF made out of aluminium, called MOF-303, that is almost 150 times cheaper and captures twice as much water compared to MOF-801.
This will enable scientists to produce a new generation of harvesters capable of producing more than 3 cups of water per day from one kilogram of MOF.
Mr Yaghi said: “There has been tremendous interest in commercialising this, and there are several startups already engaged in developing a commercial water-harvesting device.
“The aluminium MOF is making this practical for water production, because it is cheap.”
He added: “The key development here is that it operates at low humidity, because that is what it is in arid regions of the world.
“In these conditions, the harvester collects water even at sub-zero dew points.”
Mr Yaghi is awaiting his next field test, where he is set to test the alumnium-based MOF (MOF-303) in the Death Valley in late summer, where temperatures reach up to 43 degree Celsius in the day, with humidity levels as low as 25 percent.